I ran 235/35 ZR19 backs 265/30 ZR19...the overall diameter was very close to the same with this setup. The whole reason I got rid of them was the 19" looked WAY too big for the little TT. 20's IMO are going to look ridiculous but to each his own. I will never again go over 18" with my TT (with 20's you will never get the car to look low at all either)

Pics of my old 19's

 

Yeah, too big...

The lip is beautiful though

 

i know some ppl think theyre too big, i just love big wheels. Im planning on something lightweight, like a 2 or 3 peice wheel.

I assumed that as long as the overall tire was the same size on the outside that it would be fine. Now how about the weight difference between the front and back? the back will likely be 1-1.5" wider then the front. Will the extra pound or 2 make a difference at all?

 

there's a certain percentage that haldex can compensate for when running staggered. i believe it's within 7-10% of the total wheel diameter that haldex can compensate for.

i'm running staggered, 18x8.5 fronts // 18x9.5 rears. 225/40's all around... stretched

 

so why is everyone so worried about even running a new tire with 3 worn out tires, and stuff like that?

I do it all the time, but some people **** bricks if you mention replacing 1 tire without replacing the other 3 which have 5k miles on them

 

^ bc if you do, your haldex system's gonna blow!! omfgzz dunt dew it!11

 

To the OP, I hear what you are saying about keeping the overall diameter the same but look up at the picture of .clipse's TT, his overall diameter including the tire is about 22" (and those are 18's)imagine what a 20" wheel (even with an ultra low profile tire) will look like on there. 20" wheels are for Benz's, Bimmer's, Bentley's, and Ballin azz fools...Not a sports car. as far as lightweight goes good luck finding anything less than 40lbs a piece in 20" then add tire weight. my 19's were 35lbs a piece.Think it threw thoroughly before making you decision.

 

Hey... what are you doing with your stock 17s???

 

19s look perfect on the older body I think. I have abuddy who had 20s, and they did look too big, but the new TT is a little bigger and I think 20s will look perfect!
They wont be cheap but I will definatly find 20s way under 40lbs! I have 22s on my 300 and they are 42lbs each, and theyre 1 peice. a 2-3 peice 20" you can definatly find something around 30lbs!

As far as tire sizes, I havent decided, I want something agressive in the back for sure, and needless to say rubber bands for tires. Most likely going to be a 30 series in the front and a 25 in the rear.